The integrated circuit package is the building block used in an electronic system to provide applications for usage in products such as a personal computer, communications equipment, military devices, industrial robotics, aircraft, and a vast line of consumer products from automotive vehicles to kitchen appliances.
The integrated circuit such as a chip or die is a very tiny and easily damaged device that can be protected with an encapsulant. Even static electricity can be devastating to the very sensitive circuitry of the modern chip or die. Its entire internal contents both functional and physical have protection from damage during normal operating conditions as required by the electronic system in which it is used.
The integrated circuit package is typically mounted and electrically connected to a printed circuit board that is a component in an electronic system. A lead frame is commonly used inside an integrated circuit package to provide many electrical connections between the circuitry within the package and the printed circuit board within the electronic system. Often electrical connections are made with solder balls or bond wires, typically of gold or aluminum material.
The circuitry within a package consists of integrated circuits built onto one side, such as the top, of a piece of semiconductor material such as silicon chip or die. The other side of a silicon chip or die, the bottom for example, is mounted, or typically bonded, with an electrically insulating and thermally conductive die attach layer, such as epoxy onto one side of the die. The opposing die surface is free of any circuitry components such as silicon chips or dice.
The die is typically a semi-rigid electrically and thermally conductive material made of metal used for the handling and manufacturability of the integrated circuit chip or die within the confines of the integrated circuit package. The die often has an “electrical connection” to the circuitry on residing on a silicon chip or die.
There are many industry objectives with regard to integrated circuit packaging. One is for higher circuitry density per area, another is for higher performance, yet another improved reliability, and yet another is for higher profitability as a result of lower unit costs for both the silicon supplier and the electronic systems product producers.
There is a continually growing industry demand for integrated circuit packages containing electrically isolated multiple dies within a single integrated circuit package. This provides for more silicon chips or dice due to the ability to mount more than one chip or die in a single package. For example, an integrated circuit package with multiple chips or dice can have two separated and isolated groups or types of chips or dice within it. An integrated circuit package with four chips or dice can have four separated and isolated groups or types of chips or dice within it.
The practice of producing integrated circuit packages with isolated multiple chips or dice clearly addresses the objectives, namely higher density demands of the electronic industry. Another objective, higher performance, is satisfied by the fact that more than one die is isolated from other die allowing the designers to chose, mix, or match as needed from different chip or dice technologies whether proven, newly developed, or leading edge proprietary.
For those of ordinary skill in the art, are aware of the various beneficial electrical properties such as noise or cross talk reduction that results from having isolated pads within an integrated circuit package. Cost savings can result from higher density and smaller printed circuit boards.
Manufacturers use minimal attachments for multiple die attach surfaces. The minimal attachments suspend the die attach surfaces in the package during assembly. The minimal attachments allow easy separation in the completed package but poor placement control during assembly, encapsulation, or final processing.
Attempts to provide multiple die in an integrated circuit package have failed to solve manufacturability requirements such as reliability, yield, or cost. They have been plagued with unacceptable structural integrity such as issues related to mold bleeding [encapsulation conformance], poor electrical connectivity, or contamination. These issues often lead to early failure or reliability resulting in high costs or low yield.
Thus, a need still remains for an integrated circuit package system to provide improved connectivity, pricing, and dimensions. In view of the increasing demand for improved integrated circuits and particularly more connections in smaller products at lower costs, it is increasingly critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.